Radio access network mobility in non-geosynchronous satellite systems

ABSTRACT

A method is performed by a wireless device. The method includes receiving, from a network, an indication for the wireless device to prepare for a change from a first ground station to a second ground station. Each of the first ground station and the second ground station is configured to communicate with the wireless device via one or more satellites. The method further includes preparing to change from the first ground station to the second ground station. The method further includes communicating with the second ground station via the one or more satellites.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. § 371 national stage application forInternational Application No. PCT/SE2019/050880, entitled “RADIO ACCESSNETWORK MOBILITY IN NON-GEOSYNCHRONOUS SATELLITE SYSTEMS”, filed on Sep.18, 2019, the disclosures and contents of which are hereby incorporatedby reference in their entireties. Further, the present applicationclaims the benefit of and priority to U.S. Provisional PatentApplication No. 62/737,663, filed on Sep. 27, 2018, entitled “METHODSFOR CONFIGURING UE TO PREPARE FOR MOVING RAN IN NON-GEO SATELLITESYSTEMS”, the disclosure of which is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

Certain embodiments of the present disclosure relate, in general, towireless communications and, more particularly, to non-terrestrialwireless communications.

BACKGROUND

There is an ongoing resurgence of satellite communications. Severalplans for satellite networks have been announced in the past few years.The target services vary from backhaul and fixed wireless, totransportation, to outdoor mobile, to Internet-of-Things (IoT).Satellite networks could complement mobile networks on the ground byproviding connectivity to underserved areas and multicast/broadcastservices.

To benefit from the strong mobile ecosystem and economy of scale,adapting the terrestrial wireless access technologies, including LongTerm Evolution (LTE) and New Radio (NR), for satellite networks isdrawing significant interest. For example, the Third GenerationPartnership Project (3GPP) completed an initial study in Release 15 onadapting NR to support non-terrestrial networks (mainly satellitenetworks) (Technical Report TR 38.811). This initial study focused onthe channel model for the non-terrestrial networks, defining deploymentscenarios, and identifying the key potential impacts. 3GPP is conductinga follow-up study item in Release 16 on solutions evaluation for NR tosupport non-terrestrial networks (RP-181370)

Satellite Communications

A satellite radio access network (RAN) usually includes the following:

-   -   A gateway that connects a satellite network to core network    -   A satellite, referring to a space-borne platform    -   A terminal, referring to a terminal wireless device such as a        user equipment (UE)    -   A feeder link, referring to the link between a gateway and a        satellite    -   A service link, referring to the link between a satellite and a        terminal

The link from gateway to terminal is often called the forward link, andthe link from terminal to gateway is often called the return link or theaccess link. Depending on the functionality of the satellite in thesystem, two transponder options can be considered:

-   -   Bent pipe transponder: the satellite forwards the received        signal back to the earth with only amplification and a shift        from uplink frequency to downlink frequency.    -   Regenerative transponder: the satellite includes on-board        processing to demodulate and decode the received signal and        regenerate the signal before sending it back to the earth.

Depending on the orbit altitude, a satellite may be categorized as lowEarth orbit (LEO), medium Earth orbit (MEO), or geostationary (GEO)satellite.

-   -   LEO: typical heights ranging from 250-1,500 km, with orbital        periods ranging from 90-130 minutes.    -   MEO: typical heights ranging from 5,000-25,000 km, with orbital        periods ranging from 2-14 hours.    -   GEO: height at about 35,786 km, with an orbital period of 24        hours.

A communication satellite typically generates several beams over a givenarea. The footprint of a beam is usually in an elliptic shape, which hasbeen traditionally considered as a cell. The footprint of a beam is alsooften referred to as a spotbeam. The footprint of a beam may move overthe earth surface with the satellite movement or may be earth fixed withsome beam pointing mechanism used by the satellite to compensate for itsmotion. The size of a spotbeam depends on the system design, which mayrange from tens of kilometers to a few thousands of kilometers. FIG. 1shows an example architecture of a satellite network with bent pipetransponders.

In the 3GPP RAN #80 meeting, a new study item (SI) “Solutions for NR tosupport Non Terrestrial Network” was agreed (RP-108370). It is acontinuation of a preceding SI “NR to support Non-Terrestrial Networks”(RP-171450), where the objective was to study the channel model for thenon-terrestrial networks, to define deployment scenarios and parameters,and to identify the key potential impacts on NR. The results arereflected in 3GPP Technical Report 38.811.

The objectives of the current SI are to evaluate solutions for theidentified key impacts from the preceding SI and to study impact onradio access network (RAN) protocols/architecture. The objectives forlayer 2 and above are:

-   -   Study the following aspects and identify related solutions if        needed: Propagation delay: Identify timing requirements and        solutions on layer 2 aspects, MAC, RLC, RRC, to support        non-terrestrial network propagation delays considering FDD and        TDD duplexing mode. This includes radio link management. [RAN2]    -   Handover: Study and identify mobility requirements and necessary        measurements that may be needed for handovers between some        non-terrestrial space-borne vehicles (such as Non Geo stationary        satellites) that move at much higher speed but over predictable        paths [RAN2, RAN1]    -   Architecture: Identify needs for the 5G's Radio Access Network        architecture to support non-terrestrial networks (e.g. handling        of network identities) [RAN3]    -   Paging: procedure adaptations in case of moving satellite foot        prints or cells

Note, the new study item does not address regulatory issues.

The coverage pattern of NTN is described in TR 38.811 in Section 4.6 asfollows:

-   -   Satellite or aerial vehicles typically generate several beams        over a given area. The foot print of the beams are typically        elliptic shape.    -   The beam footprint may be moving over the earth with the        satellite or the aerial vehicle motion on its orbit.        Alternatively, the beam foot print may be earth fixed, in such        case some beam pointing mechanisms (mechanical or electronic        steering feature) will compensate for the satellite or the        aerial vehicle motion.

TABLE 4.6-1 Typical beam footprint size Attributes GEO Non-GEO AerialBeam foot 200-1000 km 100-500 km 5-200 km print size in diameter

Typical beam patterns of various NTN access networks are depicted inFIGS. 4.6-1 of TR 38.811, as reproduced herein as FIG. 2 .

The Technical Report of the ongoing Study Item, TR 38.821, describesscenarios for the NTN work as follows:

Non-Terrestrial Network typically features the following elements [3]:

-   -   One or several sat-gateways that connect the Non-Terrestrial        Network to a public data network    -   a GEO satellite is fed by one or several sat-gateways which are        deployed across the satellite targeted coverage (e.g. regional        or even continental coverage). We assume that UE in a cell are        served by only one sat-gateway    -   A Non-GEO satellite served successively by one sat-gateway at a        time. The system ensures service and feeder link continuity        between the successive serving sat-gateways with sufficient time        duration to proceed with mobility anchoring and hand-over

Four scenarios are considered as depicted in Table 4.2-1 and aredetailed in Table 4.2-2 of TR 38.821, which are reproduced below.

TABLE 4.2-1 Reference scenarios Transparent Regenerative satellitesatellite GEO based non-terrestrial Scenario A Scenario B access networkLEO based non-terrestrial Scenario C Scenario D access network

TABLE 4.2-2 Reference scenario parameters Scenarios GEO basednon-terrestrial access LEO based non- network (Scenario A and B)terrestrial access network (Scenario C & D) Orbit type notional stationkeeping position circular orbiting around fixed in terms ofelevation/azimuth the earth with respect to a given earth point Altitude35,786 km   600 km 1,200 km Spectrum (service link) <6 GHz (e.g. 2GHz) >6 GHz (e.g. DL 20 GHz, UL 30 GHz) Max channel bandwidth  30 MHzfor band <6 GHz (service link) 400 MHz for band >6 GHz Payload ScenarioA: Transparent (including Scenario C: Transparent radio frequencyfunction only) (including radio Scenario B: regenerative (includingfrequency function only) all or part of RAN functions) Scenario D:Regenerative (including all or part of RAN functions) Inter-Satellitelink No Scenario C: No Scenario D: Yes Earth-fixed beams Yes Scenario C:No (the beams move with the satellite) Scenario D, option 1: Yes(steering beams), see note 1 Scenario D, option 2: No (the beams movewith the satellite) Max beam foot print 500 km 200 km diameter at nadirMin Elevation angle for 10° 10° both sat-gateway and user equipment Maxdistance between 40,586 km 1,932 km (600 km satellite and user altitude)equipment at min 3,131 km (1,200 km elevation angle altitude) Max RoundTrip Delay Scenario A: 562 ms (service and Scenario C: 25.76 ms(propagation delay only) feeder links) (transparent payload: Scenario B:281 ms service and feeder links) Scenario D: 12.88 ms (regenerativepayload: service link only) Max delay variation 16 ms 4.44 ms (600 km)within a beam (earth fixed 6.44 ms (1200 km) user equipment) Maxdifferential delay 1.6 ms 0.65 ms (*) within a beam Max Doppler shift(earth 0.93 ppm 24 ppm (*) fixed user equipment) Max Doppler shift 0.000045 ppm/s 0.27 ppm/s (*) variation (earth fixed user equipment) Userequipment 1000 km/h (e.g. aircraft) 500 km/h (e.g. high motion on theearth speed train) Possibly 1000 km/h (e.g. aircraft) User equipmentOmnidirectional antenna (linear polarisation), assuming antenna types 0dBi Directive antenna (up to 60 cm equivalent aperture diameter incircular polarisation) User equipment Omnidirectional antenna: UE powerclass 3 Tx power with up to 200 mW Directive antenna: up to 4 W Userequipment Omnidirectional antenna: 7 dB Noise figure Directive antenna:1.2 dB Service link 3GPP defined New Radio Feeder link 3GPP or non-3GPP3GPP or non-3GPP defined Radio interface defined Radio interface NOTE 1:Each satellite has the capability to steer beams towards fixed points onearth using beamforming techniques. This is applicable for a period oftime corresponding to the visibility time of the satellite NOTE 2: Maxdelay variation within a beam (earth fixed user equipment) is calculatedbased on Min Elevation angle for both gateway and user equipment NOTE 3:Max differential delay within a beam is calculated based on Max beamfoot print diameter at nadir

For scenario D, which is LEO with regenerative payload, both earth-fixedand earth moving beams have been listed. So, when factoring in thefixed/non-fixed beams, there is an additional scenario. The completelist of 5 scenarios in TR 38.821 is then:

-   -   Scenario A—GEO, transparent satellite, Earth-fixed beams;    -   Scenario B—GEO, regenerative satellite, Earth fixed beams;    -   Scenario C—LEO, transparent satellite, Earth-moving beams;    -   Scenario D1—LEO, regenerative satellite, Earth-fixed beams;    -   Scenario D2—LEO, regenerative satellite, Earth-moving beams.

When NR or LTE is applied to provide the connectivity via satellites, itmeans that the ground station is a RAN node. In the case where thesatellite is transparent, all RAN functionalities are on the groundwhich means the sat-gateway has whole eNB/gNB functionality. For theregenerative satellite payload, part or all, of the eNB/gNB processingmay be on the satellite.

Radio-Link failure in NR/LTE is defined and reported when a sequence ofevents occurs at the UE. The UE monitors the downlink link quality basedon the cell-specific reference signal, and compares it to the thresholdsQout and Qin. The threshold Qout is defined as the level at which thedownlink radio link cannot be reliably received. The threshold Qin isdefined as the level at which the downlink radio link quality can besignificantly more reliably received than at Qout and typicallycorresponds to 2% block error rate of a hypothetical Physical DownlinkControl Channel (PDCCH) transmission (taking into account the PhysicalControl Format Indicator Channel (PCFICH) errors in LTE).

SUMMARY

Non-Geo satellites move rapidly with respect to any given UE location.As an example, on a 2-hour orbit, a LEO satellite is in view of astationary UE from horizon to horizon for about 20 minutes. Since eachLEO satellite may have many beams, the time during which a UE stayswithin a beam is typically only a few minutes. The fast pace ofsatellite movement creates problems for paging as well as handoffs forboth stationary and moving UEs.

Unlike terrestrial framework where a cell on the ground is tied to radiocommunication with a RAN, in non-GEO satellite access network, thesatellite beams may be moving. There may be no fixed correspondencebetween cells on the ground and satellite beams. The same geographicalregion on the ground can be covered by different satellites anddifferent beams over time. When one LEO satellite's beam moves away fromthe geographical area, another LEO satellite's beam (e.g., generated bythe same LEO satellite or by a neighboring LEO satellite) may beexpected to come in and cover the same geographical area. From the UE'sperspective, this may mean that the ground serving RAN node changes whenthe gateway changes. This situation is not present in normal terrestrialnetworks.

Accordingly, there exist certain challenges. In a moving RAN, the groundstation for the satellite (“sat-gateway”) changes as the satellitemoves, as illustrated in FIG. 3 . FIG. 3 illustrates an examplesituation of a satellite changing from gateway 1 to gateway 2.

A non-GEO satellite is served successively by one sat-gateway at a time.That means that the UE can keep the connection to the satellite, whilethe satellite changes the ground station. There are several issuesrelated to changing the ground station while preserving the physicalcell identity (PCI) of the first gateway. For example there may be anidle period of the satellite transmission, when the satellite switchesits connection to the first gateway to the second gateway. Further, thetiming advance values configured towards the first gateway would berequired to be updated to the second gateway. Moreover, the downlinktiming based on the distance/delay of the combined distance or timingdelay between the UE, satellite and gateway would require updated. Forexample, the example distance T1+T3 of FIG. 3 may be updated to the newdistance T1+T2, representing the change from Gateway 1 to Gateway 2.

Certain aspects of the present disclosure and their embodiments mayprovide solutions to these or other challenges. For example, certainembodiments provide methods for handling UE mobility when the RAN nodeswitches while the UE is connected via NR/LTE air interface. In brief,the methods are used to prepare the UE with an RRC configuration for theupcoming change of sat-gateway. Certain embodiments provide systeminformation parameters to assist IDLE mode UEs for a RAN switch. Thereare, proposed herein, various embodiments which address one or more ofthe issues disclosed herein.

According to an embodiment, a method is performed by a wireless device.The method includes receiving, from a network, an indication for thewireless device to prepare for a change from a first ground station to asecond ground station. Each of the first ground station and the secondground station is configured to communicate with the wireless device viaone or more satellites. The method further includes preparing to changefrom the first ground station to the second ground station. The methodfurther includes communicating with the second ground station via theone or more satellites.

According to another embodiment, a computer program product includes anon-transitory computer readable medium storing computer readableprogram code. The computer readable program code comprises program codeoperable to perform the above method.

According to yet another embodiment, a wireless device comprises amemory configured to store instructions and processing circuitryconfigured to execute the instructions. The wireless device isconfigured to receive, from a network, an indication for the wirelessdevice to prepare for a change from a first ground station to a secondground station. Each of the first ground station and the second groundstation is configured to communicate with the wireless device via one ormore satellites. The wireless device is further configured to prepare tochange from the first ground station to the second ground station. Thewireless device is further configured to communicate with the secondground station via the one or more satellites.

In certain embodiments, the method/wireless device/computer programproduct may have one or more additional and/or optional features, suchas one or more of the following:

In particular embodiments, the indication is received while the wirelessdevice is in a connected mode.

In particular embodiments, the indication is received via radio resourcecontrol (RRC) signaling.

In particular embodiments, the indication is received while the wirelessdevice is in idle mode.

In particular embodiments, the indication is received via a broadcastmessage.

In particular embodiments, the indication is received via the one ormore satellites.

In particular embodiments, the indication comprises one or moreparameters that the wireless device uses to prepare for the change tothe second ground station. In some embodiments, the parameters compriseone or more of: an indication whether a physical cell identity (PCI)associated with a cell providing coverage to the wireless device willchange in connection with changing to the second ground station; anindication of a change in system information; an indication of a changeof any radio access network (RAN) identification; an indication of achange of a timing advance (TA) assumption; an indication of a change ofdownlink frequency; and an indication of a change of uplink frequencyadjustment assumption. In some embodiments, the indication furtherindicates a time when the one or more parameters are valid. In someembodiments, the time is indicated based on a timer or based on when aprimary or secondary cell is at a configured elevation angle.

In particular embodiments, the indication indicates a time when thechange from the first ground station to the second ground station willoccur.

In particular embodiments, the indication indicates to start a connecteddiscontinuous reception (DRX) during the change from the first groundstation to the second ground station.

In particular embodiments, the method/wireless device/computer programproduct further includes using a first configuration prior to the changefrom the first ground station to the second ground station and using asecond, different configuration when preparing for the change from thefirst ground station to the second ground station. In some embodiments,the second configuration is based on one or more of the parameterscomprising one or more of: an indication whether a physical cellidentity (PCI) associated with a cell providing coverage to the wirelessdevice will change in connection with changing to the second groundstation; an indication of a change in system information; an indicationof a change of any radio access network (RAN) identification; anindication of a change of a timing advance (TA) assumption; anindication of a change of downlink frequency; and an indication of achange of uplink frequency adjustment assumption.

In particular embodiments, the method/wireless device/computer programproduct further includes sending a response message via the one or moresatellites. The response message comprises at least one of: aconfirmation that the wireless device received the indication to preparefor the change from the first ground station to the second groundstation; a confirmation that the wireless device has applied aconfiguration associated with changing to the second ground station; andan indication that the wireless device has failed to apply theconfiguration associated with changing to the second ground station.

In particular embodiments, preparing for the change from the firstground station to the second ground station comprises adjusting one ormore parameters or assumptions associated with Radio Link Failure (RLF)during the change from the first ground station to the second groundstation.

According to an embodiment, a method is performed by a network node. Themethod includes determining that a wireless device should prepare for achange from a first ground station to a second ground station. Each ofthe first ground station and the second ground station is configured tocommunicate with the wireless device via one or more satellites. Themethod further includes sending an indication to the wireless deviceindicating that the wireless device should prepare for the change fromthe first ground station to the second ground station.

According to another embodiment, a computer program product includes anon-transitory computer readable medium storing computer readableprogram code. The computer readable program code comprises program codeoperable to perform the method immediately above.

According to another embodiment, a network node comprises a memoryconfigured to store instructions and processing circuitry configured toexecute the instructions. The network node is configured to determinethat a wireless device should prepare for a change from a first groundstation to a second ground station. Each of the first ground station andthe second ground station is configured to communicate with the wirelessdevice via one or more satellites. The network node is furtherconfigured to send an indication to the wireless device indicating thatthe wireless device should prepare for the change from the first groundstation to the second ground station.

In certain embodiments, the method/network node/computer program productmay have one or more additional and/or optional features, such as one ormore of the following:

In particular embodiments, the indication is sent while the wirelessdevice is in a connected mode.

In particular embodiments, the indication is sent via radio resourcecontrol (RRC) signaling.

In particular embodiments, the indication is sent while the wirelessdevice is in idle mode.

In particular embodiments, the indication is sent via a broadcastmessage.

In particular embodiments, the indication is sent via the one or moresatellites.

In particular embodiments, the network node is implemented on one of theone or more satellites.

In particular embodiments, the method/network node/computer programproduct further includes determining one or more parameters that thewireless device is to use to prepare for the change to the second groundstation. The indication indicates the one or more parameters to thewireless device. In some embodiments, the parameters comprise one ormore of: an indication whether a physical cell identity (PCI) associatedwith a cell providing coverage to the wireless device will change inconnection with changing to the second ground station; an indication ofa change in system information; an indication of a change of any radioaccess network (RAN) identification; an indication of a change of atiming advance (TA) assumption; an indication of a change of downlinkfrequency; and an indication of a change of uplink frequency adjustmentassumption. In some embodiments, the indication further indicates a timewhen the one or more parameters are valid. In some embodiments, the timeis indicated based on a timer or based on when a primary or secondarycell is at a configured elevation angle.

In particular embodiments, the indication indicates a time when thechange from the first ground station to the second ground station willoccur.

In particular embodiments, the indication further indicates to start aconnected discontinuous reception (DRX) during the change from the firstground station to the second ground station.

In particular embodiments, the method/network node/computer programproduct further includes using a first configuration to communicate withthe wireless device prior to the change from the first ground station tothe second ground station and using a second, different configuration tocommunicate with the wireless device in response to changing from thefirst ground station to the second ground station. In some embodiments,the second configuration is based on one or more of the parameterscomprising one of more of: an indication whether a physical cellidentity (PCI) associated with a cell providing coverage to the wirelessdevice will change in connection with changing to the second groundstation; an indication of a change in system information; an indicationof a change of any radio access network (RAN) identification; anindication of a change of a timing advance (TA) assumption; anindication of a change of downlink frequency; and an indication of achange of uplink frequency adjustment assumption.

In particular embodiments, the method/network node/computer programproduct further includes receiving a response message from the wirelessdevice. The response message comprising at least one of: a confirmationthat the wireless device received the indication to prepare for thechange from the first ground station to the second ground station; aconfirmation that the wireless device has applied a configurationassociated with changing to the second ground station; or an indicationthat the wireless device has failed to apply the configurationassociated with changing to the second ground station.

In particular embodiments, the indication further indicates that thewireless device is to adjust one or more parameters or assumptionsassociated with Radio Link Failure (RLF) during the change from thefirst ground station to the second ground station.

Certain embodiments may provide one or more of the following technicaladvantages. For example, certain embodiments introduce signaling optionsto support smoother switching of satellite gateways fornon-geostationary satellite network nodes. An abrupt switch may causethe loss of the UE Radio Resource Control (RRC) connection. As a result,the UE may be required to enter an IDLE mode and start searching for anew cell for which the reference signals may not be immediately ready.Additionally, if the RRC connection is ended, measurements may berequired to be reconfigured after the UE is in connected mode again(e.g., once UE has managed to find and attach to new cell). As anotherexample, certain embodiments avoid multiple simultaneous uplinktransmissions from many UEs during a change of satellite gateways. Forexample, a handover for all UEs during a switch of gateways will lead tolarge amount of signaling at the same time. Similarly, multiple UEsdeclaring radio-link failure, e.g., due to a change of gateway, willlead to a high number of UEs trying to perform new random accessrequests. Certain embodiments may reduce the signaling associated with aground station switch by indicating a pending or anticipated switch ofsatellite gateways.

Certain embodiments may have none, some, or all of the above-recitedadvantages. Other advantages may be readily apparent to one having skillin the art.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed embodiments and theirfeatures and advantages, reference is now made to the followingdescription, taking in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an non-terrestrial wireless communications network,in accordance with certain embodiments;

FIG. 2 illustrates a pair of non-terrestrial network configurations, inaccordance with certain embodiments;

FIG. 3 illustrates an example satellite network node changing gateways,in accordance with certain embodiments;

FIG. 4 illustrates an example wireless network, in accordance withcertain embodiments;

FIG. 5 illustrates an example user equipment, in accordance with certainembodiments;

FIG. 6 illustrates an example virtualization environment, in accordancewith certain embodiments;

FIG. 7 illustrate an example telecommunication network connected via anintermediate network to a host computer, in accordance with certainembodiments;

FIG. 8 illustrates an example host computer communicating via a basestation with a user equipment over a partially wireless connection, inaccordance with certain embodiments;

FIG. 9 is a flowchart illustrating an example method implemented in acommunication system, in accordance certain embodiments;

FIG. 10 is a flowchart illustrating a second example method implementedin a communication system, in accordance with certain embodiments;

FIG. 11 is a flowchart illustrating a third method implemented in acommunication system, in accordance with certain embodiments;

FIG. 12 is a flowchart illustrating a fourth method implemented in acommunication system, in accordance with certain embodiments;

FIG. 13 illustrates a first example method performed by a wirelessdevice, in accordance with certain embodiments;

FIG. 14 illustrates a second example method performed by a wirelessdevice, in accordance with certain embodiments;

FIG. 15 illustrates a schematic block diagram of a first exampleapparatus in a wireless network, in accordance with certain embodiments;and

FIG. 16 illustrates a third example method performed by a wirelessdevice, in accordance with certain embodiments; and

FIG. 17 illustrates an example method performed by a network node, inaccordance with certain embodiments.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described morefully with reference to the accompanying drawings. Other embodiments,however, are contained within the scope of the subject matter disclosedherein, the disclosed subject matter should not be construed as limitedto only the embodiments set forth herein; rather, these embodiments areprovided by way of example to convey the scope of the subject matter tothose skilled in the art.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features,and advantages of the enclosed embodiments will be apparent from thefollowing description.

Although certain aspects of the present disclosure describe problems andsolutions using NR terminology, it should be understood that the samesolutions apply to LTE as well where applicable.

The present disclosure provides several methods to mitigate the problemsrelated to a switch of ground sat-gateways. Certain embodiments mayimpart the same or different advantages depending on the particularnetworking scenario, implementation, or architecture of the networkSeveral categories of embodiments are disclosed herein that mayincorporate one or more of the features detailed below.

For Connected Mode Wireless Devices

In a first set of embodiments, a wireless device, e.g., a UE, can be RRCconfigured (e.g., configured via signaling on a control channel) to beprepared for an upcoming switch of the RAN (e.g., between RANs atdifferent satellite gateways (sat-gateways)). According to someembodiments, the configuration provided to the wireless device mayinclude one or more parameters. For example, in some embodiments, theanticipated RAN switch time may be a parameter in the configuration tothe UE. Time may be expressed as a common time reference between RAN andUEs, such as an absolute time (e.g., GPS time, UTC time) or a commonreference in relation to system frame number (SFN) in the radio frames.This may include when the downlink (DL) reference signal (RS) isswitched off and/or switch ON. As another example, in some embodiments,an indication whether the Physical Cell Identity (PCI) will change ornot may be include in the configuration. In some embodiments, theindication may include or not include the new PCI that will take over ifit changes. Accordingly, the wireless device may be informed whether,after the RAN switch, the same PCI will be sent from the satellitetaking over the geographical area or if it uses different PCI.

In certain embodiments, one or more of the following may be included inthe configuration of the wireless device in anticipation of a change insatellite gateways:

-   -   An indication of the switch or change of any RAN information    -   An indication of change in system information may be included in        the configuration    -   An indication of a change of the timing advance (TA) assumption    -   An indication of a change of downlink frequency    -   An indication of a change of uplink frequency adjustment        assumption        Any of the above potential indications may be further, according        to some embodiments, with one or more time indications when        (e.g., for how long or in what time period(s)) the respective        indications are valid.

According to certain embodiments, the wireless device may be indicatedto start connected mode DRX while the switch happens. In someembodiments, the configuration may indicate an inactive period that islonger than currently specified (e.g., using the current satellitegateway). Further, in some embodiments, the indication may indicatewhether to do a random access procedure (RACH) after the switch (e.g.,when starting the next active period). In this manner, the UE maydetermine whether to assume the same TA or the same average TA after theswitch.

According to certain embodiments, the wireless device receives anindication of when the configuration becomes valid. For example, in someembodiments, the configuration also includes a time, time range, ortimer for which the configuration is valid. In some embodiments, thewireless device is provided with one or more conditions to apply theconfiguration. For example, the wireless device may be instructed toswitch to the other RRC configuration when a primary or a secondary cellis at a configured elevation angle, position, or other condition.

In certain embodiments, the wireless device, e.g., UE, may be configuredto send a response to the RRC configuration. In some embodiments, thewireless device communicates a confirmation at reception of RRCconfiguration. In some embodiments, a confirmation when theconfiguration is applied may be sent. For example, there may be one ormore conditions that should be satisfied for the configuration to becomevalid. If the configuration fails, the wireless device may communicate afailure in response to indicate the failed application of theconfiguration. As a result, a new configuration may be provided oralternative procedures may be carried out by the wireless device and/ornetwork.

In certain embodiments, the wireless device may be configured to behavein a particular way during the RAN switch. For example, Radio LinkFailure (RLF) related parameters and assumptions may be configureddifferently during the RAN switch to keep the wireless device connectedduring the switch. In some embodiments, the RLF related parameters mayinclude one or more of the following:

-   -   N number of out-of-sync indications needed to start an RLF timer    -   N number of automatic repeat request (ARQ) retransmissions to        declare an RLF    -   An indication to stop the wireless device from monitoring for        RLF for a period of time    -   An indication to stop an RLF timer if running        In this manner, the wireless device may be prevented from        inappropriately declaring an RLF during a switch of gateways.

For Inactive/Idle Mode Wireless Devices

In a second set of embodiments, a wireless device, e.g., a UE, can beRRC configured (e.g., configured via signaling on a control channel) tobe prepared for an upcoming switch of the RAN (e.g., between RANs atdifferent satellite gateways (sat-gateways)). Since the wireless devicemay be in an inactive or idle mode, the network may broadcast a messagethat may be used by the wireless device in switching RANs. In certainembodiments, the broadcast message from the network may indicate one ormore of the following:

-   -   The time when the RAN switch will happen. Time may be expressed        as a common time reference between RAN and UEs, such as an        absolute time (e.g., GPS time, UTC time) or a common reference        in relation to system frame number (SFN) in the radio frames.        This may include when the DL RS is switched off and/or switch        ON.    -   An indication if PCI will change or not. In some embodiments,        with the new PCI that will take over. Alternatively, in other        embodiments, without the new PCI.    -   An indication of a change in the system information    -   An indication of a switch of any RAN identification    -   An indication of a change of the TA assumption    -   An indication of a change of the downlink frequency    -   An indication of a change of the uplink frequency adjustment        assumption    -   The above may be with time indication when these are valid

Any of the above potential indications may be further, according to someembodiments, with one or more time indications when (e.g., for how longor in what time period(s)) the respective indications are valid.

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to a wirelessnetwork, such as the example wireless network illustrated in FIG. 4 .For simplicity, the wireless network of FIG. 4 only depicts network 106,network nodes 160 and 160 b, and WDs 110, 110 b, and 110 c. In practice,a wireless network may further include any additional elements suitableto support communication between wireless devices or between a wirelessdevice and another communication device, such as a landline telephone, aservice provider, or any other network node or end device. Of theillustrated components, network node 160 and wireless device (WD) 110are depicted with additional detail. The wireless network may providecommunication and other types of services to one or more wirelessdevices to facilitate the wireless devices' access to and/or use of theservices provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless localarea network (WLAN) standards, such as the IEEE 802.11 standards; and/orany other appropriate wireless communication standard, such as theWorldwide Interoperability for Microwave Access (WiMax), Bluetooth,Z-Wave and/or ZigBee standards.

Network 106 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 160 and WD 110 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 4 , network node 160 includes processing circuitry 170, devicereadable medium 180, interface 190, auxiliary equipment 184, powersource 186, power circuitry 187, and antenna 162. Although network node160 illustrated in the example wireless network of FIG. 4 may representa device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 160 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 180 may comprise multiple separate hard drives aswell as multiple RAM modules).

Similarly, network node 160 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 160comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeB's.In such a scenario, each unique NodeB and RNC pair, may in someinstances be considered a single separate network node. In someembodiments, network node 160 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate device readable medium 180 for thedifferent RATs) and some components may be reused (e.g., the sameantenna 162 may be shared by the RATs). Network node 160 may alsoinclude multiple sets of the various illustrated components fordifferent wireless technologies integrated into network node 160, suchas, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wirelesstechnologies. These wireless technologies may be integrated into thesame or different chip or set of chips and other components withinnetwork node 160.

Processing circuitry 170 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 170 may include processing informationobtained by processing circuitry 170 by, for example, converting theobtained information into other information, comparing the obtainedinformation or converted information to information stored in thenetwork node, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Processing circuitry 170 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 160 components, such as device readable medium 180, network node160 functionality. For example, processing circuitry 170 may executeinstructions stored in device readable medium 180 or in memory withinprocessing circuitry 170. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 170 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 170 may include one or more ofradio frequency (RF) transceiver circuitry 172 and baseband processingcircuitry 174. In some embodiments, radio frequency (RF) transceivercircuitry 172 and baseband processing circuitry 174 may be on separatechips (or sets of chips), boards, or units, such as radio units anddigital units. In alternative embodiments, part or all of RF transceivercircuitry 172 and baseband processing circuitry 174 may be on the samechip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 170executing instructions stored on device readable medium 180 or memorywithin processing circuitry 170. In alternative embodiments, some or allof the functionality may be provided by processing circuitry 170 withoutexecuting instructions stored on a separate or discrete device readablemedium, such as in a hard-wired manner. In any of those embodiments,whether executing instructions stored on a device readable storagemedium or not, processing circuitry 170 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 170 alone or to other components ofnetwork node 160, but are enjoyed by network node 160 as a whole, and/orby end users and the wireless network generally.

Device readable medium 180 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 170. Device readable medium 180 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 170 and, utilized by network node 160. Devicereadable medium 180 may be used to store any calculations made byprocessing circuitry 170 and/or any data received via interface 190. Insome embodiments, processing circuitry 170 and device readable medium180 may be considered to be integrated.

Interface 190 is used in the wired or wireless communication ofsignalling and/or data between network node 160, network 106, and/or WDs110. As illustrated, interface 190 comprises port(s)/terminal(s) 194 tosend and receive data, for example to and from network 106 over a wiredconnection. Interface 190 also includes radio front end circuitry 192that may be coupled to, or in certain embodiments a part of, antenna162. Radio front end circuitry 192 comprises filters 198 and amplifiers196. Radio front end circuitry 192 may be connected to antenna 162 andprocessing circuitry 170. Radio front end circuitry may be configured tocondition signals communicated between antenna 162 and processingcircuitry 170. Radio front end circuitry 192 may receive digital datathat is to be sent out to other network nodes or WDs via a wirelessconnection. Radio front end circuitry 192 may convert the digital datainto a radio signal having the appropriate channel and bandwidthparameters using a combination of filters 198 and/or amplifiers 196. Theradio signal may then be transmitted via antenna 162. Similarly, whenreceiving data, antenna 162 may collect radio signals which are thenconverted into digital data by radio front end circuitry 192. Thedigital data may be passed to processing circuitry 170. In otherembodiments, the interface may comprise different components and/ordifferent combinations of components.

In certain alternative embodiments, network node 160 may not includeseparate radio front end circuitry 192, instead, processing circuitry170 may comprise radio front end circuitry and may be connected toantenna 162 without separate radio front end circuitry 192. Similarly,in some embodiments, all or some of RF transceiver circuitry 172 may beconsidered a part of interface 190. In still other embodiments,interface 190 may include one or more ports or terminals 194, radiofront end circuitry 192, and RF transceiver circuitry 172, as part of aradio unit (not shown), and interface 190 may communicate with basebandprocessing circuitry 174, which is part of a digital unit (not shown).

Antenna 162 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 162 may becoupled to radio front end circuitry 190 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 162 may comprise one or more omni-directional,sector or panel antennas operable to transmit/receive radio signalsbetween, for example, 2 GHz and 66 GHz. An omni-directional antenna maybe used to transmit/receive radio signals in any direction, a sectorantenna may be used to transmit/receive radio signals from deviceswithin a particular area, and a panel antenna may be a line of sightantenna used to transmit/receive radio signals in a relatively straightline. In some instances, the use of more than one antenna may bereferred to as MIMO. In certain embodiments, antenna 162 may be separatefrom network node 160 and may be connectable to network node 160 throughan interface or port.

Antenna 162, interface 190, and/or processing circuitry 170 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 162, interface 190, and/or processing circuitry 170 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 187 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node 160with power for performing the functionality described herein. Powercircuitry 187 may receive power from power source 186. Power source 186and/or power circuitry 187 may be configured to provide power to thevarious components of network node 160 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 186 may either be included in,or external to, power circuitry 187 and/or network node 160. Forexample, network node 160 may be connectable to an external power source(e.g., an electricity outlet) via an input circuitry or interface suchas an electrical cable, whereby the external power source supplies powerto power circuitry 187. As a further example, power source 186 maycomprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 187. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 160 may include additionalcomponents beyond those shown in FIG. 4 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 160 may include user interface equipment to allow input ofinformation into network node 160 and to allow output of informationfrom network node 160. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node160.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE). a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a WD mayrepresent a machine or other device that performs monitoring and/ormeasurements, and transmits the results of such monitoring and/ormeasurements to another WD and/or a network node. The WD may in thiscase be a machine-to-machine (M2M) device, which may in a 3GPP contextbe referred to as an MTC device. As one particular example, the WD maybe a UE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g. refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 110 includes antenna 111, interface 114,processing circuitry 120, device readable medium 130, user interfaceequipment 132, auxiliary equipment 134, power source 136 and powercircuitry 137. WD 110 may include multiple sets of one or more of theillustrated components for different wireless technologies supported byWD 110, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, orBluetooth wireless technologies, just to mention a few. These wirelesstechnologies may be integrated into the same or different chips or setof chips as other components within WD 110.

Antenna 111 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 114. In certain alternative embodiments, antenna 111 may beseparate from WD 110 and be connectable to WD 110 through an interfaceor port. Antenna 111, interface 114, and/or processing circuitry 120 maybe configured to perform any receiving or transmitting operationsdescribed herein as being performed by a WD. Any information, dataand/or signals may be received from a network node and/or another WD. Insome embodiments, radio front end circuitry and/or antenna 111 may beconsidered an interface.

As illustrated, interface 114 comprises radio front end circuitry 112and antenna 111. Radio front end circuitry 112 comprise one or morefilters 118 and amplifiers 116. Radio front end circuitry 114 isconnected to antenna 111 and processing circuitry 120, and is configuredto condition signals communicated between antenna 111 and processingcircuitry 120. Radio front end circuitry 112 may be coupled to or a partof antenna 111. In some embodiments, WD 110 may not include separateradio front end circuitry 112; rather, processing circuitry 120 maycomprise radio front end circuitry and may be connected to antenna 111.Similarly, in some embodiments, some or all of RF transceiver circuitry122 may be considered a part of interface 114. Radio front end circuitry112 may receive digital data that is to be sent out to other networknodes or WDs via a wireless connection. Radio front end circuitry 112may convert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 118and/or amplifiers 116. The radio signal may then be transmitted viaantenna 111. Similarly, when receiving data, antenna 111 may collectradio signals which are then converted into digital data by radio frontend circuitry 112. The digital data may be passed to processingcircuitry 120. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

Processing circuitry 120 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 110components, such as device readable medium 130, WD 110 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry120 may execute instructions stored in device readable medium 130 or inmemory within processing circuitry 120 to provide the functionalitydisclosed herein.

As illustrated, processing circuitry 120 includes one or more of RFtransceiver circuitry 122, baseband processing circuitry 124, andapplication processing circuitry 126. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry120 of WD 110 may comprise a SOC. In some embodiments, RF transceivercircuitry 122, baseband processing circuitry 124, and applicationprocessing circuitry 126 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry124 and application processing circuitry 126 may be combined into onechip or set of chips, and RF transceiver circuitry 122 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 122 and baseband processing circuitry124 may be on the same chip or set of chips, and application processingcircuitry 126 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 122,baseband processing circuitry 124, and application processing circuitry126 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 122 may be a part of interface114. RF transceiver circuitry 122 may condition RF signals forprocessing circuitry 120.

In certain embodiments, some or all of the functionality describedherein as being performed by a WD may be provided by processingcircuitry 120 executing instructions stored on device readable medium130, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 120 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner. In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 120 can be configured to perform the describedfunctionality. The benefits provided by such functionality are notlimited to processing circuitry 120 alone or to other components of WD110, but are enjoyed by WD 110 as a whole, and/or by end users and thewireless network generally.

Processing circuitry 120 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 120, may include processinginformation obtained by processing circuitry 120 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 110, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 130 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 120. Device readable medium 130 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 120. In someembodiments, processing circuitry 120 and device readable medium 130 maybe considered to be integrated.

User interface equipment 132 may provide components that allow for ahuman user to interact with WD 110. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment132 may be operable to produce output to the user and to allow the userto provide input to WD 110. The type of interaction may vary dependingon the type of user interface equipment 132 installed in WD 110. Forexample, if WD 110 is a smart phone, the interaction may be via a touchscreen; if WD 110 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 132 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 132 is configured to allow input of information into WD 110,and is connected to processing circuitry 120 to allow processingcircuitry 120 to process the input information. User interface equipment132 may include, for example, a microphone, a proximity or other sensor,keys/buttons, a touch display, one or more cameras, a USB port, or otherinput circuitry. User interface equipment 132 is also configured toallow output of information from WD 110, and to allow processingcircuitry 120 to output information from WD 110. User interfaceequipment 132 may include, for example, a speaker, a display, vibratingcircuitry, a USB port, a headphone interface, or other output circuitry.Using one or more input and output interfaces, devices, and circuits, ofuser interface equipment 132, WD 110 may communicate with end usersand/or the wireless network, and allow them to benefit from thefunctionality described herein.

Auxiliary equipment 134 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 134 may vary depending on the embodiment and/or scenario.

Power source 136 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 110 may further comprise power circuitry 137for delivering power from power source 136 to the various parts of WD110 which need power from power source 136 to carry out anyfunctionality described or indicated herein. Power circuitry 137 may incertain embodiments comprise power management circuitry. Power circuitry137 may additionally or alternatively be operable to receive power froman external power source; in which case WD 110 may be connectable to theexternal power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 137 may also in certain embodiments be operable to deliverpower from an external power source to power source 136. This may be,for example, for the charging of power source 136. Power circuitry 137may perform any formatting, converting, or other modification to thepower from power source 136 to make the power suitable for therespective components of WD 110 to which power is supplied.

FIG. 5 illustrates one embodiment of a UE in accordance with variousaspects described herein. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser (e.g., a smart sprinkler controller). Alternatively, a UE mayrepresent a device that is not intended for sale to, or operation by, anend user but which may be associated with or operated for the benefit ofa user (e.g., a smart power meter). UE 220 may be any UE identified bythe 3^(rd) Generation Partnership Project (3GPP), including a NB-IoT UE,a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.UE 200, as illustrated in FIG. 5 , is one example of a WD configured forcommunication in accordance with one or more communication standardspromulgated by the 3^(rd) Generation Partnership Project (3GPP), such as3GPP's GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, theterm WD and UE may be used interchangeable. Accordingly, although FIG. 5is a UE, the components discussed herein are equally applicable to a WD,and vice-versa.

In FIG. 5 , UE 200 includes processing circuitry 201 that is operativelycoupled to input/output interface 205, radio frequency (RF) interface209, network connection interface 211, memory 215 including randomaccess memory (RAM) 217, read-only memory (ROM) 219, and storage medium221 or the like, communication subsystem 231, power source 233, and/orany other component, or any combination thereof. Storage medium 221includes operating system 223, application program 225, and data 227. Inother embodiments, storage medium 221 may include other similar types ofinformation. Certain UEs may utilize all of the components shown in FIG.5 , or only a subset of the components. The level of integration betweenthe components may vary from one UE to another UE. Further, certain UEsmay contain multiple instances of a component, such as multipleprocessors, memories, transceivers, transmitters, receivers, etc.

In FIG. 5 , processing circuitry 201 may be configured to processcomputer instructions and data. Processing circuitry 201 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 201 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 205 may be configuredto provide a communication interface to an input device, output device,or input and output device. UE 200 may be configured to use an outputdevice via input/output interface 205. An output device may use the sametype of interface port as an input device. For example, a USB port maybe used to provide input to and output from UE 200. The output devicemay be a speaker, a sound card, a video card, a display, a monitor, aprinter, an actuator, an emitter, a smartcard, another output device, orany combination thereof. UE 200 may be configured to use an input devicevia input/output interface 205 to allow a user to capture informationinto UE 200. The input device may include a touch-sensitive orpresence-sensitive display, a camera (e.g., a digital camera, a digitalvideo camera, a web camera, etc.), a microphone, a sensor, a mouse, atrackball, a directional pad, a trackpad, a scroll wheel, a smartcard,and the like. The presence-sensitive display may include a capacitive orresistive touch sensor to sense input from a user. A sensor may be, forinstance, an accelerometer, a gyroscope, a tilt sensor, a force sensor,a magnetometer, an optical sensor, a proximity sensor, another likesensor, or any combination thereof. For example, the input device may bean accelerometer, a magnetometer, a digital camera, a microphone, and anoptical sensor.

In FIG. 5 , RF interface 209 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. Network connection interface 211 may beconfigured to provide a communication interface to network 243 a.Network 243 a may encompass wired and/or wireless networks such as alocal-area network (LAN), a wide-area network (WAN), a computer network,a wireless network, a telecommunications network, another like networkor any combination thereof. For example, network 243 a may comprise aWi-Fi network. Network connection interface 211 may be configured toinclude a receiver and a transmitter interface used to communicate withone or more other devices over a communication network according to oneor more communication protocols, such as Ethernet, TCP/IP, SONET, ATM,or the like. Network connection interface 211 may implement receiver andtransmitter functionality appropriate to the communication network links(e.g., optical, electrical, and the like). The transmitter and receiverfunctions may share circuit components, software or firmware, oralternatively may be implemented separately.

RAM 217 may be configured to interface via bus 202 to processingcircuitry 201 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 219 maybe configured to provide computer instructions or data to processingcircuitry 201. For example, ROM 219 may be configured to store invariantlow-level system code or data for basic system functions such as basicinput and output (I/O), startup, or reception of keystrokes from akeyboard that are stored in a non-volatile memory. Storage medium 221may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 221 may be configured toinclude operating system 223, application program 225 such as a webbrowser application, a widget or gadget engine or another application,and data file 227. Storage medium 221 may store, for use by UE 200, anyof a variety of various operating systems or combinations of operatingsystems.

Storage medium 221 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 221 may allow UE 200 to access computer-executable instructions,application programs or the like, stored on transitory or non-transitorymemory media, to off-load data, or to upload data. An article ofmanufacture, such as one utilizing a communication system may betangibly embodied in storage medium 221, which may comprise a devicereadable medium.

In FIG. 5 , processing circuitry 201 may be configured to communicatewith network 243 b using communication subsystem 231. Network 243 a andnetwork 243 b may be the same network or networks or different networkor networks. Communication subsystem 231 may be configured to includeone or more transceivers used to communicate with network 243 b. Forexample, communication subsystem 231 may be configured to include one ormore transceivers used to communicate with one or more remotetransceivers of another device capable of wireless communication such asanother WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.2,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 233 and/or receiver 235 to implement transmitter orreceiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 233 andreceiver 235 of each transceiver may share circuit components, softwareor firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 231 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 231 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 243 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network243 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 213 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 200.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 200 or partitioned acrossmultiple components of UE 200. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem231 may be configured to include any of the components described herein.Further, processing circuitry 201 may be configured to communicate withany of such components over bus 202. In another example, any of suchcomponents may be represented by program instructions stored in memorythat when executed by processing circuitry 201 perform the correspondingfunctions described herein. In another example, the functionality of anyof such components may be partitioned between processing circuitry 201and communication subsystem 231. In another example, thenon-computationally intensive functions of any of such components may beimplemented in software or firmware and the computationally intensivefunctions may be implemented in hardware.

FIG. 6 is a schematic block diagram illustrating a virtualizationenvironment 300 in which functions implemented by some embodiments maybe virtualized. In the present context, virtualizing means creatingvirtual versions of apparatuses or devices which may includevirtualizing hardware platforms, storage devices and networkingresources. As used herein, virtualization can be applied to a node(e.g., a virtualized base station or a virtualized radio access node) orto a device (e.g., a UE, a wireless device or any other type ofcommunication device) or components thereof and relates to animplementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 300 hosted byone or more of hardware nodes 330. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 320 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 320 are run invirtualization environment 300 which provides hardware 330 comprisingprocessing circuitry 360 and memory 390. Memory 390 containsinstructions 395 executable by processing circuitry 360 wherebyapplication 320 is operative to provide one or more of the features,benefits, and/or functions disclosed herein.

Virtualization environment 300, comprises general-purpose orspecial-purpose network hardware devices 330 comprising a set of one ormore processors or processing circuitry 360, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 390-1 which may benon-persistent memory for temporarily storing instructions 395 orsoftware executed by processing circuitry 360. Each hardware device maycomprise one or more network interface controllers (NICs) 370, alsoknown as network interface cards, which include physical networkinterface 380. Each hardware device may also include non-transitory,persistent, machine-readable storage media 390-2 having stored thereinsoftware 395 and/or instructions executable by processing circuitry 360.Software 395 may include any type of software including software forinstantiating one or more virtualization layers 350 (also referred to ashypervisors), software to execute virtual machines 340 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 340, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 350 or hypervisor. Differentembodiments of the instance of virtual appliance 320 may be implementedon one or more of virtual machines 340, and the implementations may bemade in different ways.

During operation, processing circuitry 360 executes software 395 toinstantiate the hypervisor or virtualization layer 350, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 350 may present a virtual operating platform thatappears like networking hardware to virtual machine 340.

As shown in FIG. 6 , hardware 330 may be a standalone network node withgeneric or specific components. Hardware 330 may comprise antenna 3225and may implement some functions via virtualization. Alternatively,hardware 330 may be part of a larger cluster of hardware (e.g. such asin a data center or customer premise equipment (CPE)) where manyhardware nodes work together and are managed via management andorchestration (MANO) 3100, which, among others, oversees lifecyclemanagement of applications 320.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 340 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 340, and that part of hardware 330 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 340, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 340 on top of hardware networking infrastructure330 and corresponds to application 320 in FIG. 6 .

In some embodiments, one or more radio units 3200 that each include oneor more transmitters 3220 and one or more receivers 3210 may be coupledto one or more antennas 3225. Radio units 3200 may communicate directlywith hardware nodes 330 via one or more appropriate network interfacesand may be used in combination with the virtual components to provide avirtual node with radio capabilities, such as a radio access node or abase station.

In some embodiments, some signalling can be effected with the use ofcontrol system 3230 which may alternatively be used for communicationbetween the hardware nodes 330 and radio units 3200.

With reference to FIG. 7 , in accordance with an embodiment, acommunication system includes telecommunication network 410, such as a3GPP-type cellular network, which comprises access network 411, such asa radio access network, and core network 414. Access network 411comprises a plurality of base stations 412 a, 412 b, 412 c, such as NBs,eNBs, gNBs or other types of wireless access points, each defining acorresponding coverage area 413 a, 413 b, 413 c. Each base station 412a, 412 b, 412 c is connectable to core network 414 over a wired orwireless connection 415. A first UE 491 located in coverage area 413 cis configured to wirelessly connect to, or be paged by, thecorresponding base station 412 c. A second UE 492 in coverage area 413 ais wirelessly connectable to the corresponding base station 412 a. Whilea plurality of UEs 491, 492 are illustrated in this example, thedisclosed embodiments are equally applicable to a situation where a soleUE is in the coverage area or where a sole UE is connecting to thecorresponding base station 412.

Telecommunication network 410 is itself connected to host computer 430,which may be embodied in the hardware and/or software of a standaloneserver, a cloud-implemented server, a distributed server or asprocessing resources in a server farm. Host computer 430 may be underthe ownership or control of a service provider, or may be operated bythe service provider or on behalf of the service provider. Connections421 and 422 between telecommunication network 410 and host computer 430may extend directly from core network 414 to host computer 430 or may govia an optional intermediate network 420. Intermediate network 420 maybe one of, or a combination of more than one of, a public, private orhosted network; intermediate network 420, if any, may be a backbonenetwork or the Internet; in particular, intermediate network 420 maycomprise two or more sub-networks (not shown).

The communication system of FIG. 7 as a whole enables connectivitybetween the connected UEs 491, 492 and host computer 430. Theconnectivity may be described as an over-the-top (OTT) connection 450.Host computer 430 and the connected UEs 491, 492 are configured tocommunicate data and/or signaling via OTT connection 450, using accessnetwork 411, core network 414, any intermediate network 420 and possiblefurther infrastructure (not shown) as intermediaries. OTT connection 450may be transparent in the sense that the participating communicationdevices through which OTT connection 450 passes are unaware of routingof uplink and downlink communications. For example, base station 412 maynot or need not be informed about the past routing of an incomingdownlink communication with data originating from host computer 430 tobe forwarded (e.g., handed over) to a connected UE 491. Similarly, basestation 412 need not be aware of the future routing of an outgoinguplink communication originating from the UE 491 towards the hostcomputer 430.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 8 . In communication system500, host computer 510 comprises hardware 515 including communicationinterface 516 configured to set up and maintain a wired or wirelessconnection with an interface of a different communication device ofcommunication system 500. Host computer 510 further comprises processingcircuitry 518, which may have storage and/or processing capabilities. Inparticular, processing circuitry 518 may comprise one or moreprogrammable processors, application-specific integrated circuits, fieldprogrammable gate arrays or combinations of these (not shown) adapted toexecute instructions. Host computer 510 further comprises software 511,which is stored in or accessible by host computer 510 and executable byprocessing circuitry 518. Software 511 includes host application 512.Host application 512 may be operable to provide a service to a remoteuser, such as UE 530 connecting via OTT connection 550 terminating at UE530 and host computer 510. In providing the service to the remote user,host application 512 may provide user data which is transmitted usingOTT connection 550.

Communication system 500 further includes base station 520 provided in atelecommunication system and comprising hardware 525 enabling it tocommunicate with host computer 510 and with UE 530. Hardware 525 mayinclude communication interface 526 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 500, as well as radiointerface 527 for setting up and maintaining at least wirelessconnection 570 with UE 530 located in a coverage area (not shown in FIG.5 ) served by base station 520. Communication interface 526 may beconfigured to facilitate connection 560 to host computer 510. Connection560 may be direct or it may pass through a core network (not shown inFIG. 8 ) of the telecommunication system and/or through one or moreintermediate networks outside the telecommunication system. In theembodiment shown, hardware 525 of base station 520 further includesprocessing circuitry 528, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 520 further has software 521 storedinternally or accessible via an external connection.

Communication system 500 further includes UE 530 already referred to.Its hardware 535 may include radio interface 537 configured to set upand maintain wireless connection 570 with a base station serving acoverage area in which UE 530 is currently located. Hardware 535 of UE530 further includes processing circuitry 538, which may comprise one ormore programmable processors, application-specific integrated circuits,field programmable gate arrays or combinations of these (not shown)adapted to execute instructions. UE 530 further comprises software 531,which is stored in or accessible by UE 530 and executable by processingcircuitry 538. Software 531 includes client application 532. Clientapplication 532 may be operable to provide a service to a human ornon-human user via UE 530, with the support of host computer 510. Inhost computer 510, an executing host application 512 may communicatewith the executing client application 532 via OTT connection 550terminating at UE 530 and host computer 510. In providing the service tothe user, client application 532 may receive request data from hostapplication 512 and provide user data in response to the request data.OTT connection 550 may transfer both the request data and the user data.Client application 532 may interact with the user to generate the userdata that it provides.

It is noted that host computer 510, base station 520 and UE 530illustrated in FIG. 8 may be similar or identical to host computer 430,one of base stations 412 a, 412 b, 412 c and one of UEs 491, 492 of FIG.7 , respectively. This is to say, the inner workings of these entitiesmay be as shown in FIG. 8 and independently, the surrounding networktopology may be that of FIG. 7 .

In FIG. 8 , OTT connection 550 has been drawn abstractly to illustratethe communication between host computer 510 and UE 530 via base station520, without explicit reference to any intermediary devices and theprecise routing of messages via these devices. Network infrastructuremay determine the routing, which it may be configured to hide from UE530 or from the service provider operating host computer 510, or both.While OTT connection 550 is active, the network infrastructure mayfurther take decisions by which it dynamically changes the routing(e.g., on the basis of load balancing consideration or reconfigurationof the network).

Wireless connection 570 between UE 530 and base station 520 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 530 using OTT connection 550,in which wireless connection 570 forms the last segment. More precisely,the teachings of these embodiments may improve the latency and therebyprovide benefits such as reduced user waiting time and betterresponsiveness.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 550 between host computer510 and UE 530, in response to variations in the measurement results.The measurement procedure and/or the network functionality forreconfiguring OTT connection 550 may be implemented in software 511 andhardware 515 of host computer 510 or in software 531 and hardware 535 ofUE 530, or both. In embodiments, sensors (not shown) may be deployed inor in association with communication devices through which OTTconnection 550 passes; the sensors may participate in the measurementprocedure by supplying values of the monitored quantities exemplifiedabove, or supplying values of other physical quantities from whichsoftware 511, 531 may compute or estimate the monitored quantities. Thereconfiguring of OTT connection 550 may include message format,retransmission settings, preferred routing etc.; the reconfiguring neednot affect base station 520, and it may be unknown or imperceptible tobase station 520. Such procedures and functionalities may be known andpracticed in the art. In certain embodiments, measurements may involveproprietary UE signaling facilitating host computer 510's measurementsof throughput, propagation times, latency and the like. The measurementsmay be implemented in that software 511 and 531 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 550 while it monitors propagation times, errors etc.

FIG. 9 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 7 and 8 . Forsimplicity of the present disclosure, only drawing references to FIG. 9will be included in this section. In step 610, the host computerprovides user data. In substep 611 (which may be optional) of step 610,the host computer provides the user data by executing a hostapplication. In step 620, the host computer initiates a transmissioncarrying the user data to the UE. In step 630 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 640 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 10 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 7 and 8 . Forsimplicity of the present disclosure, only drawing references to FIG. 10will be included in this section. In step 710 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step720, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 730 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 11 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 7 and 8 . Forsimplicity of the present disclosure, only drawing references to FIG. 11will be included in this section. In step 810 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 820, the UE provides user data. In substep 821(which may be optional) of step 820, the UE provides the user data byexecuting a client application. In substep 811 (which may be optional)of step 810, the UE executes a client application which provides theuser data in reaction to the received input data provided by the hostcomputer. In providing the user data, the executed client applicationmay further consider user input received from the user. Regardless ofthe specific manner in which the user data was provided, the UEinitiates, in substep 830 (which may be optional), transmission of theuser data to the host computer. In step 840 of the method, the hostcomputer receives the user data transmitted from the UE, in accordancewith the teachings of the embodiments described throughout thisdisclosure.

FIG. 12 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 7 and 8 . Forsimplicity of the present disclosure, only drawing references to FIG. 12will be included in this section. In step 910 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 920 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step 930(which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

FIG. 13 depicts a method in accordance with particular embodiments, themethod begins at step 1302 with from a network, an indication that thewireless device should prepare for a change from a first ground stationto a second ground station, each ground station adapted to communicatewith the wireless device via one or more satellites. The methodcontinues to step 1304 with preparing for the change from the firstground station to the second ground station.

FIG. 14 depicts a method in accordance with particular embodiments, themethod begins at step 1412 with determining that a wireless deviceshould prepare for a change from a first ground station to a secondground station, each ground station adapted to communicate with thewireless device via one or more satellites. The method continues to step1414 with sending an indication to the wireless device indicating thatthe wireless device should prepare for the change from the first groundstation to the second ground station.

FIG. 15 illustrates a schematic block diagram of an apparatus 1500 in awireless network (for example, the wireless network shown in FIG. 4 ).The apparatus may be implemented in a wireless device or network node(e.g., wireless device 110 or network node 160 shown in FIG. 4 ).Apparatus 1500 is operable to carry out the example method(s) describedwith reference to FIGS. 13 and 14 and possibly any other processes ormethods disclosed herein. It is also to be understood that the methodsof FIGS. 13 and 14 are not necessarily carried out solely by apparatus1500. At least some operations of the method can be performed by one ormore other entities.

Virtual Apparatus 1500 may comprise processing circuitry, which mayinclude one or more microprocessor or microcontrollers, as well as otherdigital hardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory, cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein, in several embodiments. In someimplementations, the processing circuitry may be used to causedetermining unit 1502, configuring unit 1504, communicating unit 1506,and any other suitable units of apparatus 1500 to perform correspondingfunctions according one or more embodiments of the present disclosure.

As illustrated in FIG. 15 , apparatus 1500 includes determining unit1502, configuring unit 1504, and communicating unit 1506. In certainembodiments, determining unit 1502 is configured to determine when achange from a first ground station and a second ground station willoccur. In certain embodiments, determining unit 1502 is configured todetermine parameters to be used by a wireless device to prepare forchanging from the first ground station and the second ground station(e.g., parameters that should be used during and/or after changing tothe second ground station). In certain embodiments, the determining maybe performed based on detecting/analysing network conditions and/orbased on information obtained from a network node (e.g., a groundstation or satellite). In certain embodiments, configuring unit 1504 isconfigured to apply a first configuration prior to changing to thesecond ground station and to apply a second, different configurationduring and/or after changing to the second ground station. In certainembodiments, communicating unit 1506 facilitates communication betweenthe wireless device and the network. As an example, communicating unit1506 may be configured to receive an indication from the networkindicating that the wireless device should prepare for a change from afirst ground station to a second ground station (and may optionally senda response) when communicating unit 1506 is implemented in the wirelessdevice. As another example, communicating unit 1506 may be configured tosend the wireless device an indication that the wireless device shouldprepare for a change from a first ground station to a second groundstation (and optionally receive a response from the wireless device)when communicating unit 1506 is implemented in a network node (e.g.,ground station or satellite).

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

SAMPLE EMBODIMENTS Group A Embodiments

1. A method performed by a wireless device, the method comprising:

-   -   receiving, from a network, an indication that the wireless        device should prepare for a change from a first ground station        to a second ground station, each ground station adapted to        communicate with the wireless device via one or more satellites;        and    -   preparing for the change from the first ground station to the        second ground station.

2. The method of the previous embodiment, wherein the indication isreceived while the wireless device is in connected mode.

3. The method of any of the previous embodiments, wherein the indicationis received via radio resource control (RRC) signaling.

4. The method of embodiment 1, wherein the indication is received whilethe wireless device is in idle mode.

5. The method of any of the previous embodiments, wherein the indicationis received via a broadcast message.

6. The method of any of the previous embodiments, wherein the indicationis received via the one or more satellites.

7. The method of any of the previous embodiments, wherein the indicationcomprises one or more parameters that the wireless device uses toprepare for the change to the second ground station.

8. The method of any of the previous embodiment, wherein the parameterscomprise one or more of:

-   -   an indication whether a physical cell identity (PCI) associated        with a cell providing coverage to the wireless device will        change in connection with changing to the second ground station;    -   an indication of a change in system information;    -   an indication of a change of any radio access network (RAN)        identification;    -   an indication of a change of a timing advance (TA) assumption;    -   an indication of a change of downlink frequency; and    -   an indication of a change of uplink frequency adjustment        assumption.

9. The method of any of embodiments 7-8, wherein the indication furtherindicates a time when the one or more parameters are valid.

10. The method of the previous embodiment, where the time is indicatedbased on a timer or based on when a primary or secondary cell is at aconfigured elevation angle.

11. The method of any of the previous embodiments, wherein theindication indicates a time when the change from the first groundstation to the second ground station will occur.

12. The method of any of the previous embodiments, wherein theindication further indicates to start a connected discontinuousreception (DRX) while the change from the first ground station to thesecond ground station occurs.

13. The method of any of the previous embodiments, further comprising:

-   -   using a first configuration prior to the change from the first        ground station to the second ground station; and    -   using a second, different configuration when preparing for the        change from the first ground station to the second ground        station.

14. The method of the previous embodiment, wherein the secondconfiguration is based on one or more of the parameters of exampleembodiment 8.

15. The method of any of the previous embodiments, further comprisingsending a response message via the one or more satellites, the responsemessage comprising at least one of:

-   -   a confirmation that the wireless device received the indication        to prepare for the change from the first ground station to the        second ground station,    -   a confirmation that the wireless device has applied a        configuration associated with changing to the second ground        station; or    -   an indication that the wireless device has failed to apply the        configuration associated with changing to the second ground        station.

16. The method of any of the previous claims, wherein preparing for thechange from the first ground station to the second ground stationfurther comprises:

-   -   adjusting one or more parameters or assumptions associated with        Radio Link Failure (RLF) during the change from the first ground        station to the second ground station.

17. The method of any of the previous embodiments, further comprising:

-   -   providing user data; and    -   forwarding the user data to a host computer via the transmission        to the base station.

Group B Embodiments

18. A method performed by a network node, the method comprising:

-   -   determining that a wireless device should prepare for a change        from a first ground station to a second ground station, each        ground station adapted to communicate with the wireless device        via one or more satellites; and    -   sending an indication to the wireless device indicating that the        wireless device should prepare for the change from the first        ground station to the second ground station.

19. The method of the previous embodiment, wherein the indication issent while the wireless device is in connected mode.

20. The method of any of the previous embodiments, wherein theindication is sent via radio resource control (RRC) signaling.

21. The method of embodiment 18, wherein the indication is sent whilethe wireless device is in idle mode.

22. The method of any of the previous embodiments, wherein theindication is sent via a broadcast message.

23. The method of any of the previous embodiments, wherein theindication is sent via the one or more satellites.

24. The method of any of the previous embodiments, wherein the networknode is one of the satellites.

25. The method of any of the previous embodiments, further comprising:

-   -   determining one or more parameters that the wireless device is        to use to prepare for the change to the second ground station;    -   wherein the indication indicates the one or more parameters to        the wireless device.

26. The method of any of the previous embodiment, wherein the parameterscomprise one or more of:

-   -   an indication whether a physical cell identity (PCI) associated        with a cell providing coverage to the wireless device will        change in connection with changing to the second ground station;    -   an indication of a change in system information;    -   an indication of a change of any radio access network (RAN)        identification;    -   an indication of a change of a timing advance (TA) assumption;    -   an indication of a change of downlink frequency; and    -   an indication of a change of uplink frequency adjustment        assumption.

27. The method of any of embodiments 25-26, wherein the indicationfurther indicates a time when the one or more parameters are valid.

28. The method of the previous embodiment, where the time is indicatedbased on a timer or based on when a primary or secondary cell is at aconfigured elevation angle.

29. The method of any of the previous embodiments, wherein theindication indicates a time when the change from the first groundstation to the second ground station will occur.

30. The method of any of the previous embodiments, wherein theindication further indicates to start a connected discontinuousreception (DRX) while the change from the first ground station to thesecond ground station occurs.

31. The method of any of the previous embodiments, further comprising:

-   -   using a first configuration to communicate with the wireless        device prior to the change from the first ground station to the        second ground station; and    -   using a second, different configuration to communicate with the        wireless device in response to changing from the first ground        station to the second ground station.

32. The method of the previous embodiment, wherein the secondconfiguration is based on one or more of the parameters of exampleembodiment 26.

33. The method of any of the previous embodiments, further comprisingreceiving a response message from the wireless device, the responsemessage comprising at least one of:

-   -   a confirmation that the wireless device received the indication        to prepare for the change from the first ground station to the        second ground station,    -   a confirmation that the wireless device has applied a        configuration associated with changing to the second ground        station; or    -   an indication that the wireless device has failed to apply the        configuration associated with changing to the second ground        station.

34. The method of any of the previous claims, wherein the indicationfurther indicates that the wireless device is to adjust one or moreparameters or assumptions associated with Radio Link Failure (RLF)during the change from the first ground station to the second groundstation.

35. The method of any of the previous embodiments, further comprising:

-   -   obtaining user data; and    -   forwarding the user data to a host computer or a wireless        device.

Group C Embodiments

36. A wireless device, the wireless device comprising:

-   -   processing circuitry configured to perform any of the steps of        any of the Group A embodiments; and    -   power supply circuitry configured to supply power to the        wireless device.

37. A network node, the base station comprising:

-   -   processing circuitry configured to perform any of the steps of        any of the Group B embodiments;    -   power supply circuitry configured to supply power to the base        station.

38. A user equipment (UE), the UE comprising:

-   -   an antenna configured to send and receive wireless signals;    -   radio front-end circuitry connected to the antenna and to        processing circuitry, and configured to condition signals        communicated between the antenna and the processing circuitry;    -   the processing circuitry being configured to perform any of the        steps of any of the Group A embodiments;    -   an input interface connected to the processing circuitry and        configured to allow input of information into the UE to be        processed by the processing circuitry;    -   an output interface connected to the processing circuitry and        configured to output information from the UE that has been        processed by the processing circuitry; and    -   a battery connected to the processing circuitry and configured        to supply power to the UE.

39. A computer program, the computer program comprising instructionswhich when executed on a computer perform any of the steps of any of theGroup A embodiments.

40. A computer program product comprising a computer program, thecomputer program comprising instructions which when executed on acomputer perform any of the steps of any of the Group A embodiments.

41. A non-transitory computer-readable storage medium or carriercomprising a computer program, the computer program comprisinginstructions which when executed on a computer perform any of the stepsof any of the Group A embodiments.

42. A computer program, the computer program comprising instructionswhich when executed on a computer perform any of the steps of any of theGroup B embodiments.

43. A computer program product comprising a computer program, thecomputer program comprising instructions which when executed on acomputer perform any of the steps of any of the Group B embodiments.

44. A non-transitory computer-readable storage medium or carriercomprising a computer program, the computer program comprisinginstructions which when executed on a computer perform any of the stepsof any of the Group B embodiments.

45. A communication system including a host computer comprising:

-   -   processing circuitry configured to provide user data; and    -   a communication interface configured to forward the user data to        a cellular network for transmission to a user equipment (UE),    -   wherein the cellular network comprises a base station having a        radio interface and processing circuitry, the base station's        processing circuitry configured to perform any of the steps of        any of the Group B embodiments.

46. The communication system of the pervious embodiment furtherincluding the base station.

47. The communication system of the previous 2 embodiments, furtherincluding the UE, wherein the UE is configured to communicate with thebase station.

48. The communication system of the previous 3 embodiments, wherein:

-   -   the processing circuitry of the host computer is configured to        execute a host application, thereby providing the user data; and    -   the UE comprises processing circuitry configured to execute a        client application associated with the host application.

49. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

-   -   at the host computer, providing user data; and    -   at the host computer, initiating a transmission carrying the        user data to the UE via a cellular network comprising the base        station, wherein the base station performs any of the steps of        any of the Group B embodiments.

50. The method of the previous embodiment, further comprising, at thebase station, transmitting the user data.

51. The method of the previous 2 embodiments, wherein the user data isprovided at the host computer by executing a host application, themethod further comprising, at the UE, executing a client applicationassociated with the host application.

52. A user equipment (UE) configured to communicate with a base station,the UE comprising a radio interface and processing circuitry configuredto performs the of the previous 3 embodiments.

53. A communication system including a host computer comprising:

-   -   processing circuitry configured to provide user data; and    -   a communication interface configured to forward user data to a        cellular network for transmission to a user equipment (UE),    -   wherein the UE comprises a radio interface and processing        circuitry, the UE's components configured to perform any of the        steps of any of the Group A embodiments.

54. The communication system of the previous embodiment, wherein thecellular network further includes a base station configured tocommunicate with the UE.

55. The communication system of the previous 2 embodiments, wherein:

-   -   the processing circuitry of the host computer is configured to        execute a host application, thereby providing the user data; and    -   the UE's processing circuitry is configured to execute a client        application associated with the host application.

56. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

-   -   at the host computer, providing user data; and    -   at the host computer, initiating a transmission carrying the        user data to the UE via a cellular network comprising the base        station, wherein the UE performs any of the steps of any of the        Group A embodiments.

57. The method of the previous embodiment, further comprising at the UE,receiving the user data from the base station.

58. A communication system including a host computer comprising:

-   -   communication interface configured to receive user data        originating from a transmission from a user equipment (UE) to a        base station,    -   wherein the UE comprises a radio interface and processing        circuitry, the UE's processing circuitry configured to perform        any of the steps of any of the Group A embodiments.

59. The communication system of the previous embodiment, furtherincluding the UE.

60. The communication system of the previous 2 embodiments, furtherincluding the base station, wherein the base station comprises a radiointerface configured to communicate with the UE and a communicationinterface configured to forward to the host computer the user datacarried by a transmission from the UE to the base station.

61. The communication system of the previous 3 embodiments, wherein:

-   -   the processing circuitry of the host computer is configured to        execute a host application; and    -   the UE's processing circuitry is configured to execute a client        application associated with the host application, thereby        providing the user data.

62. The communication system of the previous 4 embodiments, wherein:

-   -   the processing circuitry of the host computer is configured to        execute a host application, thereby providing request data; and    -   the UE's processing circuitry is configured to execute a client        application associated with the host application, thereby        providing the user data in response to the request data.

63. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

-   -   at the host computer, receiving user data transmitted to the        base station from the UE, wherein the UE performs any of the        steps of any of the Group A embodiments.

64. The method of the previous embodiment, further comprising, at theUE, providing the user data to the base station.

65. The method of the previous 2 embodiments, further comprising:

-   -   at the UE, executing a client application, thereby providing the        user data to be transmitted; and    -   at the host computer, executing a host application associated        with the client application.

66. The method of the previous 3 embodiments, further comprising:

-   -   at the UE, executing a client application; and    -   at the UE, receiving input data to the client application, the        input data being provided at the host computer by executing a        host application associated with the client application,    -   wherein the user data to be transmitted is provided by the        client application in response to the input data.

67. A communication system including a host computer comprising acommunication interface configured to receive user data originating froma transmission from a user equipment (UE) to a base station, wherein thebase station comprises a radio interface and processing circuitry, thebase station's processing circuitry configured to perform any of thesteps of any of the Group B embodiments.

68. The communication system of the previous embodiment furtherincluding the base station.

69. The communication system of the previous 2 embodiments, furtherincluding the UE, wherein the UE is configured to communicate with thebase station.

70. The communication system of the previous 3 embodiments, wherein:

-   -   the processing circuitry of the host computer is configured to        execute a host application;    -   the UE is configured to execute a client application associated        with the host application, thereby providing the user data to be        received by the host computer.

71. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

-   -   at the host computer, receiving, from the base station, user        data originating from a transmission which the base station has        received from the UE, wherein the UE performs any of the steps        of any of the Group A embodiments.

72. The method of the previous embodiment, further comprising at thebase station, receiving the user data from the UE.

73. The method of the previous 2 embodiments, further comprising at thebase station, initiating a transmission of the received user data to thehost computer.

FIG. 16 illustrates an example flowchart for a third example method 1600for use in a wireless device, such as wireless device 110 b or 110 c orwireless device 200 described above in reference to FIGS. 4 and 5 .Method 1600 may begin at step 1610 in which an indication for thewireless device to prepare for a change from a first ground station to asecond ground station is received from a network, e.g., the wirelessnetwork shown in FIG. 4 . Each of the first ground station and thesecond ground station is configured to communicate with the wirelessdevice via one or more satellites, e.g., as shown in FIGS. 2 and 3 . Asone example, the indication may be received by the wireless device viathe one or more satellites.

In certain embodiments, the indication is received while the wirelessdevice is in a connected mode, e.g., involving the first ground station.In some embodiments, the indication may be a configuration received viaradio resource control RRC. In certain embodiments, the indication isreceived while the wireless device is in a disconnected or idle mode. Insome embodiments, the indication is received via a broadcast messagefrom the network.

In certain embodiments, the indication comprises one or more parametersthat the wireless device uses to prepare for the change to the secondground station. As described above, the parameters may include one ormore of various parameters that allow the wireless device to switch moresmoothly. For example, the parameters may include one or more of anindication whether a physical cell identity (PCI) associated with a cellproviding coverage to the wireless device will change in connection withchanging to the second ground station; an indication of a change insystem information; an indication of a change of any radio accessnetwork (RAN) identification; an indication of a change of a timingadvance (TA) assumption; an indication of a change of downlinkfrequency; and an indication of a change of uplink frequency adjustmentassumption.

In certain embodiments, the indication further indicates a time when theone or more parameters are valid. In some embodiments the time isindicated based on a timer or based on when a primary or secondary cellis at a configured elevation angle. In this manner, the wireless devicemay apply the updated configuration only when it is proper (e.g., afterthe switch or after a set time after the switch begins).

In certain embodiments, the indication indicates a time when the changefrom the first ground station to the second ground station will occur.The wireless device may use this time to determine when to changeconfigurations, probe for reference signals, etc. In some embodiments,the indication indicates to start a connected discontinuous reception(DRX) during the change from the first ground station to the secondground station. Accordingly, the wireless device may save power and beprevented from declaring a radio link failure if the switch will bedelayed or take more than a predetermined period of time to complete.

At step 1620, the wireless device prepares to change from the firstground station to the second ground station. For example, the wirelessdevice may implement the information provided in the indication to readythe wireless device to switch over and communicate with the secondground station, e.g., via the one or more satellites. For example, incertain embodiments, the wireless device uses a first configurationprior to the change from the first ground station to the second groundstation and uses a second, different configuration when preparing forthe change from the first ground station to the second ground station.The second configuration may be based on one or more parametersindicated in the indication from the network and/or one or moremeasurements or determinations made by the wireless device using theprovided indication or information obtained thereupon.

In certain embodiments, the preparation includes adjusting one or moreparameters or assumptions associated with Radio Link Failure (RLF)during the change from the first ground station to the second groundstation. For example, the wireless device may adjust one of thefollowing when preparing for the switch the N number of out-of-syncindications needed to start an RLF timer or the N number of automaticrepeat request (ARQ) retransmissions to declare an RLF. Further, in someembodiments, the wireless device may stop monitoring for RLF for aperiod of time based on the provided indication. Further, in someembodiments, the indication may cause the wireless device to stop an RLFtimer if running.

At step 1630, the wireless device communicates with the second groundstation via the one or more satellites. For example, using theindication and information obtained using the indication to prepare forthe switch may allow for the wireless device to more smoothly switch tothe second ground station and communicate with the radio access networkvia the one or more satellites. As described herein, the indication mayallow the wireless device to apply a different configuration and/orchange or use one or more different parameters that aid in theswitchover. Accordingly, the wireless device may successfully switchover and communicate with reduced delay and rate of failure.

In certain embodiments, method 1600 may include one or more additionalor optional steps or substeps. For example, in certain embodiments,method 1600 includes the optional step 1640 in which a response messageis sent via the one or more satellites in response to the indicationreceived in step 1610. In some embodiments, the response includes aconfirmation that the wireless device received the indication to preparefor the change from the first ground station to the second groundstation. In some embodiments, the response includes a confirmation thatthe wireless device has applied a configuration associated with changingto the second ground station. In some embodiments, the response includesan indication that the wireless device has failed to apply theconfiguration associated with changing to the second ground station. Inthis manner, the network may be informed of the status of the wirelessdevice and whether the indication was received and applied. In someembodiments, the network may fallback to legacy or fallback techniqueswhen the configuration is not applied or no such confirmation responseis received.

FIG. 17 illustrates an example flowchart for an example method 1700 foruse in a wireless device, for use in a network node, such as networknode 160 as described above in reference to FIG. 4 . Method 1700 maybegin at 1710, in which the network node determines that a wirelessdevice, e.g., wireless device 110 b or 110 c or wireless device 200described above in reference to FIGS. 4 and 5 , should prepare for achange from a first ground station to a second ground station. Forexample, the network node may determine that given the trajectory of theone or more satellites and/or the trajectory or pattern of the beams ofthe one or more satellites, that a satellite covering the wirelessdevice may need to switch ground stations. For example, to maintaincoverage, the one or more satellites may be switched from the firstground station to the second ground station, both of which areconfigured to communicate with the wireless device via the one or moresatellites. In some embodiments, the network node is implemented on oneof the one or more satellites.

At step 1720, an indication is sent to the wireless device indicatingthat the wireless device should prepare for the change from the firstground station to the second ground station. The indication may beprovided via RRC or via a broadcast message. The indication may includeinformation that enables the wireless device to more smoothly switchbetween radio access networks represented by the different groundstations. For example, the indication may include any informationdescribed herein, e.g., in reference to FIG. 16 above, that a wirelessdevice may use to prepare for the switch.

In certain embodiments, before sending the indication to the wirelessdevice, the network node may determine one or more parameters that thewireless device is to use to prepare for the change to the second groundstation. For example, the network node may determine any of theparameters discussed herein that should be used in the switchover. Forexample, these parameters may indicate a different configuration to usewhen communicating with the second ground station as compared to thefirst ground station. As another example, the parameters may bedetermined to increase the probability that the wireless device does notinadvertently declare a radio link failure during the switch or applythe configuration at the wrong time(s). In this manner, the indicationmay indicate the one or more parameters to the wireless device. In someembodiments, the indication includes the actual parameters determined.In some embodiments, the indication includes sufficient information forthe wireless device to determine or obtain the parameters determined bythe network node.

In certain embodiments, method 1700 may include one or more additionalor optional steps or substeps. In certain embodiments, method 1700 mayinclude optional step 1730 in which the network node further receives aresponse message from the wireless device in response to the indicationcommunicated to the wireless device. The response message may include aconfirmation that the indication was received or applied or anindication of a failure to apply the new configuration.

In some embodiments a computer program, computer program product orcomputer readable storage medium comprises instructions which whenexecuted on a computer perform any of the embodiments disclosed herein.In further examples the instructions are carried on a signal or carrierand which are executable on a computer wherein when executed perform anyof the embodiments disclosed herein.

The invention claimed is:
 1. A method performed by a wireless device,the method comprising: receiving, from a network, an indication for thewireless device to prepare for a change from a first ground station to asecond ground station, wherein each of the first ground station and thesecond ground station is configured to communicate with the wirelessdevice via one or more satellites, wherein the indication indicates tostart a connected discontinuous reception (DRX) during the change fromthe first ground station to the second ground station, so that thewireless device saves power and does not declare a Radio Link Failure(RLF) if the change from the first ground station to the second groundstation takes more than a predetermined period of time to complete;preparing to change from the first ground station to the second groundstation based on the received indication; and communicating with thesecond ground station via the one or more satellites.
 2. The method ofclaim 1, wherein the indication is received via the one or moresatellites while the wireless device is in a connected mode or an idlemode; and wherein the indication is received via: radio resource control(RRC) signaling in the connected mode; or a broadcast message in theconnected mode or in the idle mode.
 3. The method of claim 1, whereinthe indication comprises one or more parameters that the wireless deviceuses to prepare for the change to the second ground station; and whereinthe one or more parameters comprises information indicating one or moreof: whether a physical cell identity (PCI) associated with a cellproviding coverage to the wireless device will change in connection withthe changing to the second ground station; a change in systeminformation; a change of any radio access network (RAN) identification;a change of a timing advance (TA) assumption; a change of downlinkfrequency; and a change of uplink frequency adjustment assumption. 4.The method of claim 3, wherein the indication further indicates a timewhen the one or more parameters are valid, and wherein the time isindicated based on a timer or based on when a primary or secondary cellis at a configured elevation angle.
 5. The method of claim 1, whereinthe indication further indicates a time when the change from the firstground station to the second ground station will occur.
 6. The method ofclaim 1, further comprising: using a first configuration prior to thechange from the first ground station to the second ground station; andusing a second configuration, different from the first configuration,when preparing for the change from the first ground station to thesecond ground station.
 7. The method of claim 6, wherein the secondconfiguration is based on one or more parameters comprising informationindicating one or more of: whether a physical cell identity (PCI)associated with a cell providing coverage to the wireless device willchange in connection with the changing to the second ground station; achange in system information; a change of any radio access network (RAN)identification; a change of a timing advance (TA) assumption; a changeof downlink frequency; and a change of uplink frequency adjustmentassumption.
 8. The method of claim 1, further comprising sending aresponse message via the one or more satellites, the response messagecomprising at least one of: a confirmation that the wireless device hasreceived the indication to prepare for the change from the first groundstation to the second ground station, a confirmation that the wirelessdevice has applied a configuration associated with the changing to thesecond ground station; and a notification that the wireless device hasfailed to apply the configuration associated with the changing to thesecond ground station.
 9. The method of claim 1, wherein the preparingfor the change from the first ground station to the second groundstation comprises: adjusting one or more parameters or assumptionsassociated with the RLF during the change from the first ground stationto the second ground station.
 10. A method performed by a network node,the method comprising: determining that a wireless device should preparefor a change from a first ground station to a second ground station,wherein each of the first ground station and the second ground stationis configured to communicate with the wireless device via one or moresatellites; and sending an indication to the wireless device indicatingthat the wireless device should prepare for the change from the firstground station to the second ground station, wherein the indicationindicates to start a connected discontinuous reception (DRX) during thechange from the first ground station to the second ground station, sothat the wireless device saves power and does not declare a Radio LinkFailure (RLF) if the change from the first ground station to the secondground station takes more than a predetermined period of time tocomplete.
 11. The method of claim 10, wherein the indication is sent viathe one or more satellites while the wireless device is in a connectedmode or an idle mode; and wherein the indication is sent via: radioresource control (RRC) signaling in the connected mode; or a broadcastmessage in the connected mode or in the idle mode.
 12. The method ofclaim 10, wherein the network node is implemented on one of the one ormore satellites.
 13. The method of claim 10, further comprising:determining one or more parameters that the wireless device is to use toprepare for the change to the second ground station, wherein theindication further indicates the one or more parameters to the wirelessdevice, and wherein the one or more parameters comprises informationindicating one or more of: whether a physical cell identity (PCI)associated with a cell providing coverage to the wireless device willchange in connection with the changing to the second ground station; achange in system information; a change of any radio access network (RAN)identification; a change of a timing advance (TA) assumption; a changeof downlink frequency; and a change of uplink frequency adjustmentassumption.
 14. The method of claim 13, wherein the indication furtherindicates a time when the one or more parameters are valid, and wherethe time is indicated based on a timer or based on when a primary orsecondary cell is at a configured elevation angle.
 15. The method ofclaim 10, wherein the indication further indicates a time when thechange from the first ground station to the second ground station willoccur.
 16. The method of claim 10, further comprising: using a firstconfiguration to communicate with the wireless device prior to thechange from the first ground station to the second ground station; andusing a second configuration, different from the first configuration, tocommunicate with the wireless device in response to the changing fromthe first ground station to the second ground station, wherein thesecond configuration is based on one or more parameters comprisinginformation indicating one or more of: whether a physical cell identity(PCI) associated with a cell providing coverage to the wireless devicewill change in connection with the changing to the second groundstation; a change in system information; a change of any radio accessnetwork (RAN) identification; a change of a timing advance (TA)assumption; a change of downlink frequency; and a change of uplinkfrequency adjustment assumption.
 17. The method of claim 10, furthercomprising receiving a response message from the wireless device, theresponse message comprising at least one of: a confirmation that thewireless device received the indication to prepare for the change fromthe first ground station to the second ground station, a confirmationthat the wireless device has applied a configuration associated with thechanging to the second ground station; or a notification that thewireless device has failed to apply the configuration associated withthe changing to the second ground station.
 18. The method of claim 10,wherein the indication further indicates that the wireless device is toadjust one or more parameters or assumptions associated with the RLFduring the change from the first ground station to the second groundstation.
 19. A wireless device, comprising: a memory configured to storeinstructions; and processing circuitry configured to execute theinstructions, wherein the wireless device is configured to: receive,from a network, an indication for the wireless device to prepare for achange from a first ground station to a second ground station, whereineach of the first ground station and the second ground station isconfigured to communicate with the wireless device via one or moresatellites, wherein the indication indicates to start a connecteddiscontinuous reception (DRX) during the change from the first groundstation to the second ground station, so that the wireless device savespower and does not declare a Radio Link Failure (RLF) if the change fromthe first ground station to the second ground station takes more than apredetermined period of time to complete; prepare to change from thefirst ground station to the second ground station based on the receivedindication; and communicate with the second ground station via the oneor more satellites.
 20. A network node, comprising: a memory configuredto store instructions; and processing circuitry configured to executethe instructions, wherein the network node is configured to: determinethat a wireless device should prepare for a change from a first groundstation to a second ground station, wherein each of the first groundstation and the second ground station is configured to communicate withthe wireless device via one or more satellites; and send an indicationto the wireless device indicating that the wireless device shouldprepare for the change from the first ground station to the secondground station, wherein the indication indicates to start a connecteddiscontinuous reception (DRX) during the change from the first groundstation to the second ground station, so that the wireless device savespower and does not declare a Radio Link Failure (RLF) if the change fromthe first ground station to the second ground station takes more than apredetermined period of time to complete.